Gulf of Aden 2000 Year Leaf Wax Isotope, TEX86, and SST Data Tierney, J.E.; Ummenhofer, C.C.; deMenocal, P.B. Tierney, J.E. Ummenhofer, C.C. deMenocal, P.B. Sea Surface Temperature Reconstruction earth science/paleoclimate/paleoceanography (delta 13C,C30 n-alkanoic acid,null,per mil VPDB,null,paleoceanography,null,isotope ratio mass spectrometry,N,higher plant leaf wax interpretation) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,glycerol dialkyl glycerol tetraether index,one standard deviation upper bound,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,BAYSPAR Bayesian calibration; based on TEX86) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,glycerol dialkyl glycerol tetraether index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,median calibrated ssts from tex86; BAYSPAR Bayesian calibration (using BAYSPAR-NRS Tierney & Tingley 2014 GCA)) earth science/paleoclimate/paleoceanography (tetraether index of 86 carbon atoms,null,null,dimensionless,null,paleoceanography,null,high-performance liquid chromatography,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,glycerol dialkyl glycerol tetraether index,one standard deviation lower bound,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,BAYSPAR Bayesian calibration; based on TEX86) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,year Common Era,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 2H,C30 n-alkanoic acid,null,per mil VSMOW,null,paleoceanography,null,isotope ratio mass spectrometry,N,higher plant leaf wax interpretation) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (P178-15P>LATITUDE 11.955>LONGITUDE 44.3) The recent decline in Horn of Africa rainfall during the March-May "long rains" season has fomented drought and famine, threatening food security in an already vulnerable region. Some attribute this decline to anthropogenic forcing, whereas others maintain that it is a feature of internal climate variability. We show that the rate of drying in the Horn of Africa during the 20th century is unusual in the context of the last 2000 years, is synchronous with recent global and regional warming, and therefore may have an anthropogenic component. In contrast to 20th century drying, climate models predict that the Horn of Africa will become wetter as global temperatures rise. The projected increase in rainfall mainly occurs during the September-November "short rains" season, in response to large-scale weakening of the Walker circulation. Most of the models overestimate short rains precipitation while underestimating long rains precipitation, causing the Walker circulation response to unrealistically dominate the annual mean. Our results highlight the need for accurate simulation of the seasonal cycle and an improved understanding of the dynamics of the long rains season to predict future rainfall in the Horn of Africa. STUDY NOTES: Gulf of Aden leaf wax isotope (dDwax and d13Cwax), TEX86 biomarker proxy data, and SST reconstructions from 2 cores spanning the past ca. 2000 years. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Tierney, J.E. Investigator : Ummenhofer, C.C. Investigator : deMenocal, P.B. 2015-10-09 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/19200 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015bc1.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015p.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015bc1.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015p.txt English https://www.ncdc.noaa.gov/paleo/study/19200 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015bc1.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2015b/tierney2015p.txt Jessica E. Tierney, Caroline C. Ummenhofer, and Peter B. deMenocal2015Past and future rainfall in the Horn of AfricaScience Advancese15006821910.1126/sciadv.1500682http://advances.sciencemag.org/content/1/9/e1500682.abstract START YEAR: 131 AD * END YEAR: 2000 AD 44.3 11.955 44.3 11.955